/* crypto/aes/aes_ige.c -*- mode:C; c-file-style: "eay" -*- */
/* ====================================================================
* Copyright (c) 2006 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
*/
#include "cryptlib.h"
#include <openssl/aes.h>
#include "aes_locl.h"
#define N_WORDS (AES_BLOCK_SIZE / sizeof(unsigned long))
typedef struct {
unsigned long data[N_WORDS];
} aes_block_t;
/* XXX: probably some better way to do this */
#if defined(__i386__) || defined(__x86_64__)
#define UNALIGNED_MEMOPS_ARE_FAST 1
#else
#define UNALIGNED_MEMOPS_ARE_FAST 0
#endif
#if UNALIGNED_MEMOPS_ARE_FAST
#define load_block(d, s) (d) = *(const aes_block_t *)(s)
#define store_block(d, s) *(aes_block_t *)(d) = (s)
#else
#define load_block(d, s) memcpy((d).data, (s), AES_BLOCK_SIZE)
#define store_block(d, s) memcpy((d), (s).data, AES_BLOCK_SIZE)
#endif
/* N.B. The IV for this mode is _twice_ the block size */
void AES_ige_encrypt(const unsigned char *in, unsigned char *out,
const unsigned long length, const AES_KEY *key,
unsigned char *ivec, const int enc)
{
unsigned long n;
unsigned long len;
OPENSSL_assert(in && out && key && ivec);
OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);
len = length / AES_BLOCK_SIZE;
if (AES_ENCRYPT == enc)
{
if (in != out &&
(UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0))
{
aes_block_t *ivp = (aes_block_t *)ivec;
aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
while (len)
{
aes_block_t *inp = (aes_block_t *)in;
aes_block_t *outp = (aes_block_t *)out;
for(n=0 ; n < N_WORDS; ++n)
outp->data[n] = inp->data[n] ^ ivp->data[n];
AES_encrypt((unsigned char *)outp->data, (unsigned char *)outp->data, key);
for(n=0 ; n < N_WORDS; ++n)
outp->data[n] ^= iv2p->data[n];
ivp = outp;
iv2p = inp;
--len;
in += AES_BLOCK_SIZE;
out += AES_BLOCK_SIZE;
}
memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
}
else
{
aes_block_t tmp, tmp2;
aes_block_t iv;
aes_block_t iv2;
load_block(iv, ivec);
load_block(iv2, ivec + AES_BLOCK_SIZE);
while (len)
{
load_block(tmp, in);
for(n=0 ; n < N_WORDS; ++n)
tmp2.data[n] = tmp.data[n] ^ iv.data[n];
AES_encrypt((unsigned char *)tmp2.data, (unsigned char *)tmp2.data, key);
for(n=0 ; n < N_WORDS; ++n)
tmp2.data[n] ^= iv2.data[n];
store_block(out, tmp2);
iv = tmp2;
iv2 = tmp;
--len;
in += AES_BLOCK_SIZE;
out += AES_BLOCK_SIZE;
}
memcpy(ivec, iv.data, AES_BLOCK_SIZE);
memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
}
}
else
{
if (in != out &&
(UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0))
{
aes_block_t *ivp = (aes_block_t *)ivec;
aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
while (len)
{
aes_block_t tmp;
aes_block_t *inp = (aes_block_t *)in;
aes_block_t *outp = (aes_block_t *)out;
for(n=0 ; n < N_WORDS; ++n)
tmp.data[n] = inp->data[n] ^ iv2p->data[n];
AES_decrypt((unsigned char *)tmp.data, (unsigned char *)outp->data, key);
for(n=0 ; n < N_WORDS; ++n)
outp->data[n] ^= ivp->data[n];
ivp = inp;
iv2p = outp;
--len;
in += AES_BLOCK_SIZE;
out += AES_BLOCK_SIZE;
}
memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
}
else
{
aes_block_t tmp, tmp2;
aes_block_t iv;
aes_block_t iv2;
load_block(iv, ivec);
load_block(iv2, ivec + AES_BLOCK_SIZE);
while (len)
{
load_block(tmp, in);
tmp2 = tmp;
for(n=0 ; n < N_WORDS; ++n)
tmp.data[n] ^= iv2.data[n];
AES_decrypt((unsigned char *)tmp.data, (unsigned char *)tmp.data, key);
for(n=0 ; n < N_WORDS; ++n)
tmp.data[n] ^= iv.data[n];
store_block(out, tmp);
iv = tmp2;
iv2 = tmp;
--len;
in += AES_BLOCK_SIZE;
out += AES_BLOCK_SIZE;
}
memcpy(ivec, iv.data, AES_BLOCK_SIZE);
memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
}
}
}
/*
* Note that its effectively impossible to do biIGE in anything other
* than a single pass, so no provision is made for chaining.
*/
/* N.B. The IV for this mode is _four times_ the block size */
void AES_bi_ige_encrypt(const unsigned char *in, unsigned char *out,
const unsigned long length, const AES_KEY *key,
const AES_KEY *key2, const unsigned char *ivec,
const int enc)
{
unsigned long n;
unsigned long len = length;
unsigned char tmp[AES_BLOCK_SIZE];
unsigned char tmp2[AES_BLOCK_SIZE];
unsigned char tmp3[AES_BLOCK_SIZE];
unsigned char prev[AES_BLOCK_SIZE];
const unsigned char *iv;
const unsigned char *iv2;
OPENSSL_assert(in && out && key && ivec);
OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);
if (AES_ENCRYPT == enc)
{
/* XXX: Do a separate case for when in != out (strictly should
check for overlap, too) */
/* First the forward pass */
iv = ivec;
iv2 = ivec + AES_BLOCK_SIZE;
while (len >= AES_BLOCK_SIZE)
{
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
out[n] = in[n] ^ iv[n];
AES_encrypt(out, out, key);
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
out[n] ^= iv2[n];
iv = out;
memcpy(prev, in, AES_BLOCK_SIZE);
iv2 = prev;
len -= AES_BLOCK_SIZE;
in += AES_BLOCK_SIZE;
out += AES_BLOCK_SIZE;
}
/* And now backwards */
iv = ivec + AES_BLOCK_SIZE*2;
iv2 = ivec + AES_BLOCK_SIZE*3;
len = length;
while(len >= AES_BLOCK_SIZE)
{
out -= AES_BLOCK_SIZE;
/* XXX: reduce copies by alternating between buffers */
memcpy(tmp, out, AES_BLOCK_SIZE);
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
out[n] ^= iv[n];
/* hexdump(stdout, "out ^ iv", out, AES_BLOCK_SIZE); */
AES_encrypt(out, out, key);
/* hexdump(stdout,"enc", out, AES_BLOCK_SIZE); */
/* hexdump(stdout,"iv2", iv2, AES_BLOCK_SIZE); */
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
out[n] ^= iv2[n];
/* hexdump(stdout,"out", out, AES_BLOCK_SIZE); */
iv = out;
memcpy(prev, tmp, AES_BLOCK_SIZE);
iv2 = prev;
len -= AES_BLOCK_SIZE;
}
}
else
{
/* First backwards */
iv = ivec + AES_BLOCK_SIZE*2;
iv2 = ivec + AES_BLOCK_SIZE*3;
in += length;
out += length;
while (len >= AES_BLOCK_SIZE)
{
in -= AES_BLOCK_SIZE;
out -= AES_BLOCK_SIZE;
memcpy(tmp, in, AES_BLOCK_SIZE);
memcpy(tmp2, in, AES_BLOCK_SIZE);
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
tmp[n] ^= iv2[n];
AES_decrypt(tmp, out, key);
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
out[n] ^= iv[n];
memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
iv = tmp3;
iv2 = out;
len -= AES_BLOCK_SIZE;
}
/* And now forwards */
iv = ivec;
iv2 = ivec + AES_BLOCK_SIZE;
len = length;
while (len >= AES_BLOCK_SIZE)
{
memcpy(tmp, out, AES_BLOCK_SIZE);
memcpy(tmp2, out, AES_BLOCK_SIZE);
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
tmp[n] ^= iv2[n];
AES_decrypt(tmp, out, key);
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
out[n] ^= iv[n];
memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
iv = tmp3;
iv2 = out;
len -= AES_BLOCK_SIZE;
in += AES_BLOCK_SIZE;
out += AES_BLOCK_SIZE;
}
}
}